OCEAN LIFE. 27 



stimuli. When cut into, it has a semi-cartilaginous hardness, 

 and fibrous bands, almost resembling tendon in their aspect, may 

 be seen to radiate from the centre of the body towards the ex- 

 tremities of the rays. There is no doubt that the movements of 

 the rays are effected by the contractions of this fibrous membrane. 

 The skeleton, or calcareous framework imbedded in the skin of 

 the Asteridse, is by no means the least remarkable part of their 

 structure. This consists of several hundred pieces, variously dis- 

 posed, and for the most part fitted together'with great accuracy; 

 being either firmly soldered to each other, as we have seen them 

 to be in the formation of the calcareous box that constitutes the 

 central portion of Ophiurus, or united by ligaments, so as to 

 allow of a considerable degree of motion to take place between 

 them, as in the rays of Ophiurus, and other asteroid forms." 

 " The star-fishes, grossly considered, might be regarded as mere 

 walking stomachs ; and the office assigned to them in the economy 

 of nature, that of devouring all sorts of garbage and offal which 

 would otherwise accumulate upon our shores. But their diet is 

 by no means exclusively limited to such materials, since crusta- 

 ceans, shell-fish of various kinds, and even small fishes, easily 

 fall victims to their voracity. Neither is the size of the prey 

 upon which they feed so diminutive as we might suppose, from a 

 mere inspection of the orifice representing the mouth ; for this is 

 not only extremely dilatable, but, as we have found to be the 

 case in the Actinioe, the stomach is occasionally partially in- 

 verted, in order more completely to embrace substances about to 

 be devoured. Shell-fishes are frequently swallowed whole, and 

 a living specimen of Chama antiquata, Lin., has been taken from 

 the digestive cavity of an Asterias, in an entire state. It appears, 

 moreover, that it is not necessary for testaceous Mollusca to be 

 absolutely swallowed, shell and all, to enable the Asteridse to ob- 

 tain possession of the inclosed animal, as they would seem to 

 have the power of attacking large oysters, to which they are 

 generally believed to be peculiarly destructive, and of eating 

 them out of their shells. The ancients believed that, in order to 

 accomplish this, the star-fish, on finding an oyster partially open, 

 "cunningly inserted one of its rays between the valves, and thus, 

 gradually insinuating itself, destroyed its victim. Modern ob- 



